# Changes in knee pain and walking speed following primary, unilateral total knee arthroplasty and their association: A systematic review and meta-analysis

## TL;DR

This study finds that knee replacement surgery reduces pain and improves walking speed for up to a year, but mobility gains decline after that.

## Contribution

The study quantifies pain and walking speed changes after TKA and identifies their association during recovery.

## Key findings

- Knee pain significantly decreased after TKA, exceeding clinically important thresholds.
- Walking speed improved by 0.12 m/s at 3 months and 0.18 m/s at 12 months.
- Mobility gains were not sustained beyond one year and were influenced by pain levels.

## Abstract

To quantify changes in knee pain and walking speed following primary, unilateral total knee arthroplasty (TKA) for knee osteoarthritis, and to examine their relationship during recovery. Walking speed is a key indicator of functional recovery and long-term health, but whether pain relief translates into improved mobility remains unclear.

A systematic review and meta-analysis was conducted following PRISMA guidelines. PubMed was searched to September 2025 for studies reporting pre- and post-TKA values of knee pain (WOMAC-pain or KOOS-pain) and self-selected walking speed in adults undergoing primary, unilateral TKA. Pooled changes were calculated using inverse-variance weighted random-effects models. Meta-regression explored associations between pain and walking speed, adjusting for covariates.

Eighteen studies (n ​= ​819; 64.1 ​% female; age 65.1 ​± ​8.3 years; body mass index 28.4 ​± ​5.9 ​kg/m2) were included. Knee pain significantly decreased by 27–36 points (WOMAC-pain) and 19–40 points (KOOS-pain), exceeding minimal clinically important differences. Walking speed increased by +0.12 ​m/s at 3 months and +0.18 ​m/s at 12 months, both exceeding the +0.1 ​m/s threshold for clinically relevant change. No significant change in speed occurred before 3 months, and a non-significant decline appeared beyond 12 months. Meta-regression revealed greater knee pain (β ​= ​−0.005, p ​< ​0.001) and use of WOMAC-pain (vs. KOOS-pain) (β ​= ​−0.224, p ​< ​0.001) predicted slower walking speed (R2 ​= ​0.48, p ​< ​0.001).

TKA yields substantial pain relief and improved walking speeds by 3–12 months. However, mobility gains are not sustained beyond one year and are influenced by pain. Postoperative care should support both symptoms and mobility to improve long-term outcomes.